You can also summon scenery & weapons.
Scenery:
Candelabra
explosivebarrel
evileye
burningbarrel
theres way more than that just don't know the names.
weapons:
you should know the weapon names.
fist (you can summon but nothing pops up)
pistol
chainsaw
shotgun
? supershotgun
chaingun
? plasmagun
bfg9000
* if you have doom builder you can use the thing list to summon various items.